/* The contents of this file are subject to the Mozilla Public License Version 
 * 1.1 (the "License"); you may not use this file except in compliance with 
 * the License. You may obtain a copy of the License at 
 * http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 * 
 * The Original Code is Libvoikko: Library of natural language processing tools.
 * The Initial Developer of the Original Code is Harri Pitkänen <hatapitk@iki.fi>.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *********************************************************************************/

package org.puimula.libvoikko;

import java.nio.charset.Charset;
import java.nio.ByteBuffer;

import com.sun.jna.Pointer;
import com.sun.jna.PointerType;

/**
 * String mapping helper for internal use only. Public due to JNA requirements.
 */
public class ByteArray extends PointerType {
    
    private static final Charset UTF8 = Charset.forName("UTF-8");
    
    /**
     * Native-to-Java string mapping
     * @param bytes
     * @return string
     */
    public static String n2s(byte[] bytes) {
        if (bytes == null) {
            return null;
        }
        return new String(bytes, UTF8);
    }
    
    /**
     * Java-to-native string mapping
     * @param string
     * @return native string
     */
    public static byte[] s2n(String string) {
        if (string == null) {
            return null;
        }
        byte[] stringBytes = string.getBytes(UTF8);
        byte[] allBytes = new byte[stringBytes.length + 1];
        System.arraycopy(stringBytes, 0, allBytes, 0, stringBytes.length);
        return allBytes;
    }

    /**
     * Java-to-native string mapping (using direct ByteBuffer)
     * @param string
     * @return native string
     */
    public static ByteBuffer s2bb(String string) {
        if (string == null) {
            return null;
        }
        byte[] stringBytes = string.getBytes(UTF8);
        ByteBuffer allBytes = ByteBuffer.allocateDirect(stringBytes.length);
        allBytes.position(0);
        allBytes.put(stringBytes);
        return allBytes;
    }

    @Override
    public String toString() {
        if (getPointer() == Pointer.NULL) {
            return null;
        }
        return n2s(getPointer().getByteArray(0L, (int) getPointer().indexOf(0L, (byte) 0)));
    }
}
